Authentic TDA1541A

[dantwomey]

Whenever I find TDA1541A's these days the first question that comes to mind is. Is it authentic? Here's a pic.




Regards,
Dan

[Extreme_Boky]

It doesn't really make any difference... even the same batch original parts sound so different you need 10 pieces to find decent sounding one.

Boky

[QSerraTico_Tico]

Originally posted by Extreme_Boky
It doesn't really make any difference... even the same batch original parts sound so different you need 10 pieces to find decent sounding one.

Boky

Huh, that's news to me!

[Andypairo]

Hi,
this one looks like the ones on sale on ebay by a HK seller, along with some identical-looking (except for the datecode 00 instead of 88) "S1" chips (but without the crown )

These combined infos make me moderately suspicious (TDA1541x markings changed during the years and chips produced 12 years later shouldn't look exactly the same, and the '88 chips shouldn't look so "freshly printed" btw).

Of course testing them will tell you something more.
Leaving out the DEM oscillator cap will prove wheter it is a "A" chip or just a TDA1541.

I made some measurements with a -40 and -60dB sine and with my (far less than ideal) setup even the dreaded TDA1541 wasn't bad at all.
A S1 (with crown), tough, was slightly better than the "regular" "A" chips (by datasheets there should be about 5dB THD difference at -60dB level). Didn't measure the S2.

Hope it helps.

Cheers

Andrea

[Bernhard]

Originally posted by Extreme_Boky
It doesn't really make any difference... even the same batch original parts sound so different you need 10 pieces to find decent sounding one.

Boky

He he, and don't forget that this chip has two channels and usually one is ok while the other is bad.
Even on S1 crowns.

Reason why I said good bye to TDA...

[Bernhard]

Originally posted by Andypairo
"S1" chips (but without the crown )


I made some measurements with a -40 and -60dB sine and with my (far less than ideal) setup even the dreaded TDA1541 wasn't bad at all.
A S1 (with crown), tough, was slightly better than the "regular" "A" chips (by datasheets there should be about 5dB THD difference at -60dB level). Didn't measure the S2.

I have a S1 without crown sourced from a player and it is very good on both channels, offered it here on trading post but nobody wanted it because it misses the crown I guess...

Most S1 are not better on -60dB than standard A and even the S2 I had wasn't.

What you can do if you have a spectrum analyzer is find one chip that is good on left channel and another that is good on right channel and use only the good channels. Much easier.

Unfortunately the TDA is not good for non os, THD on -60dB goes up significantly.

[tube-lover]

hi all,

I trust I was one of most 1541a ( different grade ) chips pass on my hand.

sorry I hadn't seen any 00 date code.

pls take care!

thx

thomas

[Andypairo]

Originally posted by Bernhard


He he, and don't forget that this chip has two channels and usually one is ok while the other is bad.
Even on S1 crowns.

Reason why I said good bye to TDA...

This happened to me too, but only on -40 and -60dB.
Not night and day but still noticeable (on measurements, 1kHz sine only). Can't comment about the sound.
The difference is actually in the chip because swapping the L/R connections on the I/V also the "worst" channel
changed.

Did you happen to notice if there is one channel that is usually better?

Cheers

Andrea

[Bernhard]

Originally posted by Andypairo

The difference is actually in the chip because swapping the L/R connections on the I/V also the "worst" channel
changed.

I do not understand that sentence.

[Bernhard]

Originally posted by Andypairo


This happened to me too, but only on -40 and -60dB.
Not night and day but still noticeable (on measurements, 1kHz sine only).
Did you happen to notice if there is one channel that is usually better?

I do only -60dB tests.

My memories concerning the TDAs are fading... but I recall problems that in some Philips players always the same channel was worse.

Last tests I did in CD880 and there were no such problems.

Channels are always different, there are two DACs on one common substrate...